The prior art color demonstrator is described in U.S. Pat. No. 2,294,465, issued Sep. 1, 1942.
Related patents include U.S. Pat. Nos.
1,866,866, issued Jul. 12, 1932, PA1 2,091,260, issued Aug. 31, 1937, PA1 2,220,527, issued Nov. 5, 1940 and
Italian Patent Number 729,218 issued Dec. 1, 1966. A related publication, which describes a color demonstrator kit, is the magazine "Signs of the Times", May 1964, page 11.
The prior art color demonstrator includes a first transparent sheet having a picture painted on its inner face and includes a second transparent sheet having a second picture painted on its inner face, the sheets being fixedly connected along one edge so that the second picture can be superimposed on the first picture, for demonstrating an exterior view and a cutaway view of a product.
One problem with the prior art color demonstrator is that it is not useful for demonstrating color combinations of backgrounds and lettering.